1回答

• 

  南波湾0

  2016-07-26 15:04:02

  if (num >= 0  && num<=999999999){
  while(num != 0){
  count++;
  num/=10;
  }
  System.out.println("它是个"+ count+"位的数！");
  } else{
  System.out.println("输入有误！");
  }

  0 0